/* vm.h: VIRTUAL MEMORY INTERFACE
 *
 * $Id$
 * Copyright (c) 2014 Ravenbrook Limited.  See end of file for license.
 */

#ifndef vm_h
#define vm_h

#include "mpmtypes.h"


/* VMStruct -- virtual memory structure
 *
 * Unlike most other datatypes we permit this structure to be moved
 * around in memory, and in particular, allocated temporarily on the
 * stack, to help with bootstrapping. Look for uses of VMCopy.
 */

#define VMSig           ((Sig)0x519B3999) /* SIGnature VM */

typedef struct VMStruct {
  Sig sig;                      /* <design/sig> */
  Size pageSize;                /* operating system page size */
  void *block;                  /* unaligned base of mmap'd memory */
  Addr base, limit;             /* aligned boundaries of reserved space */
  Size reserved;                /* total reserved address space */
  Size mapped;                  /* total mapped memory */
} VMStruct;


#define VMPageSize(vm) RVALUE((vm)->pageSize)
#define VMBase(vm) RVALUE((vm)->base)
#define VMLimit(vm) RVALUE((vm)->limit)
#define VMReserved(vm) RVALUE((vm)->reserved)
#define VMMapped(vm) RVALUE((vm)->mapped)

extern Size PageSize(void);
extern Size (VMPageSize)(VM vm);
extern Bool VMCheck(VM vm);
extern Res VMParamFromArgs(void *params, size_t paramSize, ArgList args);
extern Res VMInit(VM vmReturn, Size size, Size grainSize, void *params);
extern void VMFinish(VM vm);
extern Addr (VMBase)(VM vm);
extern Addr (VMLimit)(VM vm);
extern Res VMMap(VM vm, Addr base, Addr limit);
extern void VMUnmap(VM vm, Addr base, Addr limit);
extern Size (VMReserved)(VM vm);
extern Size (VMMapped)(VM vm);
extern void VMCopy(VM dest, VM src);


#endif /* vm_h */


/* C. COPYRIGHT AND LICENSE
 *
 * Copyright (C) 2014 Ravenbrook Limited <http://www.ravenbrook.com/>.
 * All rights reserved.  This is an open source license.  Contact
 * Ravenbrook for commercial licensing options.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 
 * 3. Redistributions in any form must be accompanied by information on how
 * to obtain complete source code for this software and any accompanying
 * software that uses this software.  The source code must either be
 * included in the distribution or be available for no more than the cost
 * of distribution plus a nominal fee, and must be freely redistributable
 * under reasonable conditions.  For an executable file, complete source
 * code means the source code for all modules it contains. It does not
 * include source code for modules or files that typically accompany the
 * major components of the operating system on which the executable file
 * runs.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
